scratch/igc 2dfef251453: Force -fno-omit-frame-pointer in igc build

[Stefan Kangas]

branch: scratch/igc
commit 2dfef251453f591c51d983c3e5148efc1d534760
Author: Stefan Kangas <stefankangas@gmail.com>
Commit: Stefan Kangas <stefankangas@gmail.com>

    Force -fno-omit-frame-pointer in igc build
    
    * configure.ac [HAVE_MPS] (MPS_CFLAGS): Force -fno-omit-frame-pointer to
    avoid register scanning bug.
    Ref. https://lists.gnu.org/r/emacs-devel/2024-09/msg00138.html
---
 configure.ac | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 885075a2f1d..dc3b154feea 100644
--- a/configure.ac
+++ b/configure.ac
@@ -5622,6 +5622,7 @@ AC_SUBST([LIBGPM])
 HAVE_MPS=no
 LIBMPS=
 IGCOBJ=
+MPS_CFLAGS=
 if test "${with_mps}" != "no"; then
   AC_CHECK_HEADER([mps.h],
     [AC_CHECK_LIB([mps], [mps_arena_create], [HAVE_MPS=yes], [], 
[$LIB_PTHREAD])])
@@ -5635,12 +5636,15 @@ if test "${with_mps}" != "no"; then
     else
       LIBMPS="-lmps $LIB_PTHREAD"
     fi
+    # Force -fno-omit-frame-pointer to avoid register scanning bug:
+    # https://github.com/Ravenbrook/mps/pull/38
+    MPS_CFLAGS="-fno-omit-frame-pointer"
   else
     AC_MSG_ERROR([The MPS library libmps is missing]):
   fi
 fi
 
-MPS_CFLAGS=
+
 if test "$REALLY_ANDROID" = "yes" && test "$with_mps" != "no"; then
   HAVE_MPS=no
   ndk_SEARCH_MODULE([mps], [MPS], [HAVE_MPS=yes])